Original subtitles

Mammals long ago invaded every habitat on Earth.

But as our world changes, so must they.

With every new challenge...

...comes a new opportunity.

And mammals have always been quick to exploit them.

These daring sea lions in Chile have become regulars

at the fish markets.

With great ingenuity...

...and a little courage,

they have found a space for themselves

in today's...

...new wild.

But not everyone necessarily welcomes them.

Dogs patrol these beaches.

Our oceans are becoming increasingly overfished...

...and these sea lions are looking for an easy meal.

But with around two million stray dogs in Chile,

visiting these beaches, for a sea lion...

...is becoming rather dangerous.

Sea lions are not used to this sort of threat.

Dogs may be domesticated,

but their pack instinct is still strong.

They tackle the sea lions one at a time.

Eventually, they force the sea lions

back towards the sea.

But all is not lost.

The sea lions are familiar with the sound

of these trolley wheels,

and know it will be worthwhile to follow.

Leftovers from the markets are thrown back into the sea.

For many wild mammals,

surviving in the modern world requires a mixture

of ingenuity,

adaptability,

and a helping hand from us.

Humans have profoundly changed

three-quarters of the Earth's surface.

And the fastest growing of these new habitats

are our cities.

Singapore.

A bustling metropolis.

Home to a group of very enterprising mammals.

This is the Zouk family,

named after a nightclub where they were first noticed.

They are smooth-coated otters,

and they hold one of the city's most sought-after territories.

But to keep it,

they have to be constantly on patrol.

17 otter families

live on Singapore Island.

Scent-marking warns other groups

to keep their distance.

Otters were absent from Singapore for some 30 years,

but after a countrywide clean-up,

they are now back,

and the urban waterways are once again full of life.

But in holding this most central territory...

...the Zouk family face a daily danger.

One wrong move could be fatal.

Thanks to a helping hand, most get across.

But two have been separated.

One of the stragglers tries his luck...

...and makes it.

But one has been left behind.

Unaware of the split,

the family continues its patrol.

The separated one...

...is now vulnerable to attack from other otter clans.

A family can travel six miles in a day.

By now, his could be almost anywhere.

His calls are drowned out by the sounds of the city.

He revisits places along the family's regular route.

But he's always too late.

Even his family's scent

is masked by the smells of city life.

He is lost.

He will have to brave the night alone...

...without the protection of his family.

But in the quiet of the dawn...

...the sounds of his clan carry down the river.

Reunited with his family,

he is safe again.

Mammals, with their great intelligence,

have found ways of living alongside us

in the most unexpected

of places.

But in Zimbabwe, on the banks of Victoria Falls,

sharing space has become a particularly formidable challenge.

In the last 50 years,

a sizeable town has grown up here.

Elephants have learnt to stay away

during daylight hours.

But as night falls,

and the streets go quiet,

they return.

Led by the matriarch,

these are the routes that the family may have used

long before the town was built.

Tonight, they pass through in silence...

...unnoticed by the human inhabitants.

But a gang of bull elephants

have followed the family into town.

And these rowdy males

find it rather harder to keep a low profile.

They've discovered how to get water from garden taps.

Their size, brashness and curiosity

can lead to serious confrontations with humans.

With the bulls having revealed their presence,

the whole group collects as much food as they can

before being driven out of town.

This time, they're rather less subtle in their approach.

Their huge appetites can make them

very demanding visitors.

Fortunately for the herd, these townsfolk

don't resent the destruction caused tonight.

Both humans and elephants are trying to work out

how to share the same place in safety.

But the family have pressed their luck far enough

for one night...

...and the matriarch leads them back

to the cover of the bush.

It's not just the growth of towns

that is reshaping the face of the planet.

Today, almost half of the world's habitable land

is being used for agriculture.

Across Southeast Asia, vast palm oil plantations

are replacing once-pristine forest.

At first sight, it seems that little else

is allowed to live in them.

But here in Malaysia,

one resourceful group of mammals

has started to visit these plantations.

Pig-tailed macaques.

The family is teaching their youngest member

what is good to eat...

...starting with fruit and seeds.

But they're about to introduce this youngster

to a less obvious meal...

...if they can find it.

A wood rat.

The rats are fast and good at hiding...

...but the family have worked out how to catch them.

The rodents nest high in the palm trees,

and the family have discovered

that this is the place to find them.

They flush them out of their hiding places.

The alpha male watches from below...

...as fleeing rats rain down around him.

He picks them off one by one.

Over 3,000 rats are caught by the macaques each year...

...an unexpected element in the diet of animals

that are often thought of as vegetarians.

The ability of mammals

to take new opportunities as they occur

and pass their skills down through the generations

has been key to their survival.

But in a rapidly changing world,

not all mammals have enough time to adapt.

As farming intensifies across the world,

it commandeers more and more of a diminishing resource.

Today, 70% of the fresh water used globally

goes straight into agriculture.

Around 4,000 litres of water are needed

to produce just 1kg of rice.

In Tanzania, the Katuma River has been diverted

to irrigate rice fields...

...but this hinders it from reaching

a neighbouring national park.

Now, for over a month during each dry season,

the river here disappears.

The hippos are forced to share the last remaining pools

with animals of all kinds.

As the water shrinks...

...feeding and drinking becomes more and more frenzied.

This dominant male hippo is forced to share

what little space is left.

His tolerance of others diminishes with the water.

The dry season continues to tighten its grip.

The birds can leave if they so wish,

and the crocodiles can bury themselves in the mud

to wait it out.

But hippos are trapped in ever-shrinking pools

and struggle to keep cool.

The large males who once fought one another

for the rights to the drying mud

are now forced together.

The dominant male, nonetheless, remains constantly on guard.

But with every day that passes,

things become even more tense.

A hippo from a rival group wanders across the plains

in search of water.

But new arrivals here are not welcome.

His cautious approach doesn't go unnoticed

by the dominant bull.

For the newcomer, this pool could be the difference

between life and death.

But the dominant bull does not want to share.

The challenger is no match.

He's forced to return

to the crushing heat of the plains...

...while the victor continues to defend his claim

to a place in the pool.

He may have won this fight,

but the battle for the future of his river

lies beyond his control,

as agriculture claims more and more of the world's water.

Today, very little of the natural world

remains beyond our influence.

Some mammals go to extreme lengths to avoid us

by living in places where humans themselves

fear to tread.

Near the frontier between Israel and Syria

lies a reminder of a fierce six-day war.

Here in the Golan Heights, around 2,000 fields

full of unexploded mines

have lain in wait for more than 50 years.

But astonishingly, life manages to continue.

Wild boar.

It's thought that their acute sense of smell

enables them to detect the explosive material

in land mines.

And it could be this that allows them to find

a safe path through danger.

And they're not alone.

Wolves.

They, too, have an acute sense of smell...

...and even manage to raise their families here.

Elsewhere, they could be shot on sight,

but here the land mines keep humans away.

But the growing wolf pack needs to eat.

And even for those with the most sophisticated noses...

...high-speed chases are best conducted outside a minefield.

They only leave their sanctuary

under the cover of darkness.

As the sun sets, the call goes out.

Now, outside the protection of the minefields,

they are at risk from human hunters...

...and must get something to eat as quickly as possible.

It's even worth tackling a porcupine,

in spite of its prickly defences.

But wild boar...

...make for easier prey.

As dawn arrives,

the pack heads back

to the comparative safety of the minefields.

These wolves have discovered an extraordinary way

to keep their families safe...

...protected by the mines that keep humans away.

Over the past 50 years,

some wildlife populations have declined

by an average of almost 70%.

But our impact started much earlier than this.

The prairies of the American Wild West

were once home to one of the greatest assemblies

of mammals on Earth.

But human settlers

reduced their numbers from tens of millions...

...to almost none.

Today, however, they are back.

Buffalo.

This iconic American animal...

...also called bison,

has returned to the prairies.

Once a year, the males assemble.

They have been attracted by the females,

who, for a few short weeks, are fertile.

The males fight for dominance.

The winners will father the most calves.

Each success will help to increase

the numbers on the plains.

But the return of the buffalo has not been entirely natural.

It's been helped and managed by humans.

At the end of the rutting season,

while they're still together, the buffalo are rounded up.

Checked over and counted,

a small proportion are separated

for human beings to eat

and to start new herds.

Today, measured by weight,

less than 6% of mammals in the world

are truly wild.

The other 94%

are our livestock, our pets...

...and ourselves.

As these buffalo wander free for most of the year,

this managed reintroduction is perhaps a middle ground.

Half a million now graze these plains once again.

We understand the importance of space for mammals,

and have created protected areas for them

all across the globe.

Africa is home to some of the most loved of all wild mammals.

Amongst them, the cheetah.

With only around 7,000 left in the wild,

protecting their habitat has become critical.

These cubs will spend the first 18 months of their lives

with their mother,

learning from her and living under her protection.

But only an estimated 1 in 20 cheetah born

will survive to adulthood.

This mother needs to hunt almost daily

to feed her growing family.

But with four cubs trailing her,

she's easily spotted.

Cheetah are the fastest mammal.

For their high-speed chases, they need open grasslands.

But the backdrop to their lives has changed.

With an estimated 69 million visitors

to protected sites in Africa each year...

...parts of the wilderness are becoming overcrowded.

There is pressure to get the best view of the kill.

As the predators start to hunt...

...so do the cars.

Wildlife experts studying the cheetahs

recommend that there should be no more than five vehicles

to each sighting.

Over 70 cars now encircle this kill.

Tourism has become essential

to fund the protection of wild areas.

Without the revenue that comes from it,

this park and its cheetah would simply not be here.

But having an assembly this size and this close

comes at a cost.

More of the cheetah's hunts fail,

and more of their kills are abandoned.

In areas of high tourism,

research has shown that the survival of cubs

is also greatly reduced.

We are in danger of loving these cheetahs to death.

It must surely be possible

to respect the animals' need for space

and at the same time enable human visitors

to have a meaningful glimpse of the wild world.

That is what must be achieved

if cheetah are to have a future on the African plains.

Finding such a balance

is as important in the ocean as it is on land.

The seas have become highways.

And the traffic is having a huge impact

on the mammals that once had these waters to themselves.

An estimated 20,000 whales die

from collisions with ships every year.

The blue whale, which can grow to 30 metres in length,

is one of the species most at risk.

For millions of years, they have cruised the oceans...

...constantly feeding as they travel.

Their sheer size protects them from predators.

But that size also makes it difficult for them

to avoid collisions with ships.

Here in Patagonia, however,

a group of scientists are trying to help.

They are tagging blue whales

to gather more information about this growing threat.

To do that, they need to reach the whales

while they are at the surface.

And that can be a very dangerous thing to do

in a small boat.

Success!

The GPS tracker is now attached,

and the casing is retrieved.

This tag will start transmitting

every time the whale surfaces.

And the data recorded by the tags is very revealing.

This blue dot shows the track of a whale

over the course of a week,

trying to navigate heavy ship traffic

whilst attempting to feed.

Thanks to this data

and the arguments made by scientists,

parts of the range of such whales

have recently been designated a marine park...

...where ship traffic and speeds will be limited...

...enabling us to share space more responsibly...

...and help protect not just our largest mammal...

...but an entire ecosystem.

The more we know about our impact on planet Earth,

the sooner we will be able

to find a balance in today's new wild.

Filming near the border of Israel and Syria

was full of challenges.

Wolves are difficult to find at the best of times,

let alone in a hostile environment.

We know this area has about 2,000 minefields,

and we know the wolves are out there somewhere.

There's only a few places we can access safely.

The team have the help of local wolf expert Itamar Yairi.

First time I saw a wolf was on the road.

Big beautiful wolf.

Green eyes.

Just crossed the road, stopped to look at me.

Something started to build.

Itamar is a carpenter,

but his passion for wolves has taken him into the field

almost every day for the past ten years.

He uses corridors between the fenced minefields,

but he must still be cautious.

It's always a danger to be in the minefield,

cos the mines are really old

and every mine can blow up

like every minute from nothing.

And over time,

weather can move mines through the soil.

Yeah, be careful, though. Ooh, yeah. Let's go.

There is no mines over there. OK.

It's like 20 metres wide without mines all over there.

To try to uncover the wolves' current movements...

...the team uses Itamar's extensive knowledge

to bug the place with camera traps.

All of this area, they come from here a lot.

Because here we got the trees and lots of animals.

With the surveillance in place, the team start their stakeout.

As the wolves leave the minefields at night,

the crew get into position before they return.

The best strategy is to creep out at dawn

and then hunker down behind one of these walls

and hope for the best.

Producer Lydia takes advantage of the high military lookout posts.

I mean, this area is hundreds of kilometres,

so trying to spot a wolf in this is...

...is like a needle in a haystack.

As time goes by, the wolves prove extremely elusive.

We're hiding from them,

and they're probably hiding from us.

So, this is another morning without seeing the wolves.

It's another disappointment, but...

...keep on going until we are out of time.

Itamar is starting to get concerned,

so the team send out a drone

to scout for signs of them.

The wolves are so difficult to film because they just don't trust you.

They don't trust anyone.

Outside the minefields,

wolves seen hunting livestock can be legally killed.

As it is world over, human-wildlife conflict

is a delicate balance.

I try to help the wolves and the people,

like 50-50.

Part of it is filming them

and show other people how the wolves live

and why they are so important.

But before the team get a chance to spot any wolves,

they're faced by yet another hurdle.

There is still military activity on this border

and drone jammers are halting any further aerial surveillance.

We've just been told there might be a bit of interference,

so we're just not putting the drone above the minefield

just in case we lose connection,

and we don't want to lose the drone.

The next day, even surveillance on foot is no longer an option.

Can you see anything?

No, it's too foggy.

Our chances of seeing wolves are low.

We can see about 20 metres, is our visibility,

and we think it's going to be like this all day.

But in the mist,

Itamar makes an encouraging discovery.

Yeah, it looks like the wolves killed it

and maybe we will see some lone wolf.

Whatever, will be good for us.

Meanwhile, Lydia is seeing whether the wolves are going

into the military bunkers

positioned just outside the minefields.

Oh, it's huge back here.

There are two bones in here. Something's brought that in.

Got a whole load of feathers.

Obviously, a... a bird's been eaten down here.

We'll put a camera trap in here

and see if it's a route anyone uses regularly.

And finally, their luck starts to change.

Porcupine going down the stairs.

That's nice.

Walking into the bunker.

He's sniffing the camera traps.

Great.

Ah, what's that?!

Fox!

Oh, that's lovely.

Sharing our HQ with all the animals.

And back at the carcass,

Itamar's hunch has also paid off.

Ooh! It's a wolf.

One wolf, two jackals.

Ah! Looks big. Nice.

The evidence of the wolves' return keeps coming in.

Here we got wolf.

Nice shots, you see? Yeah, great.

The mother.

Nice.

Oh, here is the pup, running after her.

Relieved that the wolves are safely back in the area,

the cameramen return to their positions.

We've just seen our first wolves.

We're very happy boys now.

It's running, like, happily through the minefield.

Yeah. Running back home.

They were just, like, happy running. Happy running.

They were happy. We were panicking.

And the team's success continues...

...thanks to one man's passion for these remarkable wolves.

None of this would have been possible without Itamar.

That's for sure. We would have got nothing.

Without human, they can use the minefield as a safe zone,

so it's like kind of the perfect place for wolves.

We can't ignore how special these places are.

Next time...

...the water...

...the hardest place for mammals to survive.

From fresh water pools...

...to the deep ocean,

we will uncover the extraordinary stories

that lie beneath the surface.